Wierd Response

[auxoura]

Just want to check something with the rest of the UDM drivers. I've got a 330ci with stock exhaust, superchip and sprint throttle. I want to know if the characteristics of the throttle is common or just my car. Anyway lets say i am cruising at 10% throttle @ 3k rev and I increase the throttle to about 15%. I notice that instead of the rev increasing from 3k rev, but it actually decreases about 500revs. (btw, % of throttle is not accurate) Also, i was in KL and balancing the car for a short while without pressing the the brake but with the throttle. After that, I experience that the car will jerk whenever i press the throttle to accelerate. Its asthough the car got problems with fueling. Too rich or lean. I need to drive a bit, than only the car will improve slowly. The jerk is like a sudden cut in the fuel, like a fuel cut or ignition cut feeling. Very scary. Finally is the acceleration. I find that my car got problems thinking which gear to change to. I realize that for a 3litre, the car is quite underpowerd. I need to press quite a significant amount of the car to either change gear, especially at around 80km/h. Is this because of the superchip or the sprint throttle that confuses the ecu. Sorry for the long winded-ness. Just very curious and afraid its a problem than needs to be rectified. Thanks.

 

[funfer_fahrer]

Have you checked the health of all the sensors?

 

[auxoura]

So far the OBD havent produced any light bu I am still looking for place to go to check the car. Scared of the hefty prices due to the fact that its a BMW.

Just wanted to get the community's opinion

 

[funfer_fahrer]

If you need to press the accelerator very gently from a standstill to prevent any jerk it is probably the camshaft sensor or air mass sensor. If all the sensors are OK, then probably the problem lies somewhere within the fuel system. Could be clogged fuel injector or fuel filter.

 

[auxoura]

It doesnt happen always. Just when after I balanced the car on a hill with the throttle. It jerked asthough it was lacking or had too much or fuel or air.

Im most curious about the rev thing. How when I press more throttle, the rev decreases. I know its not changing gear cause it is on a highway and I'm already on 5th. Btw, I am using an AT.

Sigh...

 

[LumKyE46]

Just want to check something with the rest of the UDM drivers.

I've got a 330ci with stock exhaust, superchip and sprint throttle. I want to know if the characteristics of the throttle is common or just my car.

Anyway lets say i am cruising at 10% throttle @ 3k rev and I increase the throttle to about 15%. I notice that instead of the rev increasing from 3k rev, but it actually decreases about 500revs. (btw, % of throttle is not accurate)

Also, i was in KL and balancing the car for a short while without pressing the the brake but with the throttle. After that, I experience that the car will jerk whenever i press the throttle to accelerate. Its asthough the car got problems with fueling. Too rich or lean. I need to drive a bit, than only the car will improve slowly. The jerk is like a sudden cut in the fuel, like a fuel cut or ignition cut feeling. Very scary.

Finally is the acceleration. I find that my car got problems thinking which gear to change to. I realize that for a 3litre, the car is quite underpowerd. I need to press quite a significant amount of the car to either change gear, especially at around 80km/h. Is this because of the superchip or the sprint throttle that confuses the ecu.

Sorry for the long winded-ness. Just very curious and afraid its a problem than needs to be rectified. Thanks.

Yes, my car 328i was exactly like that. Especially when cruising on hiway and going up a bridge, press accelarator a bit... instead of dropping to a lowgear to climb/ surge forward, the rpm decrease. Problems like yours, doesn't know which gear to change to.

Workshop at first tot it was air/pressure leaking, idling valve jam and did diagnostic... nothing appear. Oh yeah... NO indicator light was on in my panel.

Now the car is with gearbox specialist to check on the mechanical part....

 

[auxoura]

waaaa.....i hope not mechanical on the gearbox.

Its like instead of going faster, the car actually feels like sluggish, dont want to go. It feels like it slows down, than suddenly go. Split-second feeling but very noticable.

Btw, Lumky, do you have the sprint throttle also?

 

[LumKyE46]

Yup... the engine is like seizing. And so much drag on the wheels as if there're 5 ppl in the car with load which 3 months ago wasn't the case at all.
The car was flying till then...

It's jerky if I maintain at certain speed & rpm... you need to really floor the pedal in order to go forward... *sickening*.
No sprint throttle.

 

[funfer_fahrer]

It doesnt happen always. Just when after I balanced the car on a hill with the throttle. It jerked asthough it was lacking or had too much or fuel or air.

The feel of the jerk was something like somebody was hitting your rear, right?

 

[ALBundy]

Check the ignition coil suppressor. See if its cracked. If it is, means there is a leakage and hence the symptoms as per description.

Rgds

 

[auxoura]

How come so many people familiar with this problem? common?

Where is the ignition coil suppressor? I tried searchin online but they gave me nonsense. haha....

Btw...whats the OEM site again?

 

[ALBundy]

niah..here is the fish (item 3) Check and see if its cracked.

http://www.realoem.com/bmw/showparts.do?model=CB42&mospid=47444&btnr=12_0425&hg=12&fg=05

 

[auxoura]

Wah...so hard to take out and see la....lolz
Got so many to remove and check also......

 

[ALBundy]

Very fast...less than 10 minutes to check la. Remove the BMW engine cover. 2 nuts only. Then remove another 2 screws from each coil, pull out the ignition coils one by one and check. Do it in the morning when the engine is cool. The tools to get the job done is all available in the BMW tool kit. If too lazy, then go to your mechanic and ask them to check it out.

 

[auxoura]

lol.....the bmw toolkit dont have the box set to remove the nut on the cover. My spanner cant fit. How do you know about the problem? Did you experience it first hand?

Hope isnt too costly to replace

 

[ALBundy]

The BMW tool kit has the nut remover. Unless you have lost yours.

I am saying this could be one of the cause of the problem you mentioned. Why dont you try to remove and see if its cracked. Its less than 50 ringgit per suppressor.

 

[auxoura]

Cant seem to find the nut remover. Will prolly do it when I get home.....under the shade.

*Sigh, hope it solves all the problems.

 

[3er]

Mine suffers the same symptoms from Day1 out of AB. Probably need to check that too one day.

 

[auxoura]

Today I would most probably take it to MSpeed to check it out or perhaps tomorrow.

Sometimes I wonder if its just me...lolz

 

[auxoura]

Woohoo.....finally for the problem fixed. It was a faulty cam sensor. Ah Meng at MSpeed used the laptop thingy and the error came out.

Anyway changed both sensors to new. The damage was about RM700 for both.



At least it now feels like a 3litre...lol